1. Technical Field
The present invention generally relates to a drive element for an object-rotating mechanism, and in particular, to a drive element for a mechanism rotating an object on a conveyor system.
2. Description of Related Art
A mechanism described in German Patent Application 32 48 788 C2 has at least three vertically moving rollers that are rotatable around horizontal axes and jointly movable up and down, are located below the transport plane of the conveyor system in the rest position, and are lifted at least partially above the transport plane in the working position, the rollers being synchronously drivable in the working position so that the top surface of each roller moves in a direction tangent to a circle about the rotational axis of the object. In a practical embodiment, four disk-shaped rollers, each offset from each other by 90 degrees, are located as working elements in a common circle around the rotational axis. The axes of the disk-shaped rollers run parallel to the transport plane and radially relative to the rotational axis of the object. All four rollers are attached to a common supporting frame using which they may be lifted above the transport plane and lowered again below the transport plane. All four rollers are driven synchronously by drive belts.
The known mechanism is part of a strapping machine, used to wrap a strap around a package. It easily and reliably rotates the package 90 degrees between two strapping operations, so that two crossing straps may be wrapped around a package.
However, the mechanism described is quite complex, since not only the rotary drive for the disk-shaped drive elements (drive rollers), but also a lifting drive for the frame carrying these drive elements, must be provided. All drive devices are located below the strapping zone of the strapping machine. This area also contains the driving units for the strap and the sealing device, which seals the ends of the strap together after strapping. This leaves very little space for mounting the rotary drive and the lifting drive for the frame.
It may be desirable to therefore provide a rotating mechanism that has a simpler design than the known rotating mechanism.